temperature question

[ontor]

I have looked in the FAQ section

I already know that 20 degrees should complete the fermentation cycle of my first ale in 5 to 6 days,

question is. Can I do it at 16 and wait for it to finish over a longer period?

Reasons are complex, all I need to know is yes or no.

Cheers

Ontor

 

[Moley]

Welcome to the forum :

Firstly, 5-6 days is probably optimistic (most kit instructions are) and 7-10 days might be more realistic.

20°C (give or take a couple) is about the optimum temperature for most beer and wine yeasts.

I am mainly a wine maker so I can't advise about specific brewing yeasts or which might work best warmer or cooler, except that true lager yeasts should be kept cool.

For wines, there are certainly yeasts available which perform best down to 15° or up to 25°.

With the general purpose yeasts I use for the majority of my wines a typical fermentation might take 1-2 weeks at 22°, 2-3 weeks at 20°, 3-4 weeks at 18° and 4-5 weeks at 16°.

I hope that makes some sort of sense.

The simple answer is yes, you can brew at 16° but it will take at least twice as long.

Running too hot should be avoided, fermentation will be over quicker but it stresses the yeasts, they make mistakes and can produce undesirable flavours.

 

[PD]

The optimum fermentation temperatures for Ale Yeasts is between 18 - 24C
Any higher and off flavours could be produced
If the temperatures are lower the Yeast would possibly fail to work and drop out of suspension and lay on the bottom, not working and eventually dying.
Lager yeasts can work at lower temperatures.

 

[Moley]

Thanks PD, I stand corrected

So you're saying that wine yeasts will carry on working (if much slower) at low temperatures but ale yeasts might just lay down and die?

 

[Belter]

he wanted a yes or no answer.

buy some danstar Nottingham yeast and the answer is yes.

works down to 14oC

 

[PD]

I think Yeasts will always try and work even in low temps, but they will certainly not work efficiently if temps are too far outside the " norm " High temps are to be kept away from, however you may be able to make beers at lower temps if you use special yeasts.
Wine making is a different topic and I bow to your superior knowledge, bottles of ancient wines have been found in unfavourable conditions and the yeasts have still been found to be working to an extent.
I would suggest ale yeasts would be the same, but I don't think you could class it as a satisfactory process.

 

[ontor]

thanks all for your input, I have already learned a lot :

I'm away a few days next week is all so was wondering if I needed to leave the heating on whilst I was away.
I will set it to 18 degrees. This should be ok and keep things moving along from what I read in your replies.

This will provide the added advantage of a nice warm gaff when I return from a no doubt very cold Lithuania.


Anyway. its now all made up and I sit eagerly awaiting my first "bubble" of the process.


Thanks for the words

Ontor

 

[Moley]

he wanted a yes or no answer.

But you don't learn anything from a yes/no answer.

Anyway, I thought the answer was yes but PD's reply suggested it might not be that simple.

Buy some danstar Nottingham yeast and the answer is yes.

works down to 14oC

That would explain why I have had no problems when temperatures have dropped a bit, I mostly use Gervin English Ale yeast, which is Nottingham in a different packet and for half the price.

 

[Belter]

he wanted a yes or no answer.

But you don't learn anything from a yes/no answer.

Anyway, I thought the answer was yes but PD's reply suggested it might not be that simple.

Buy some danstar Nottingham yeast and the answer is yes.

works down to 14oC

That would explain why I have had no problems when temperatures have dropped a bit, I mostly use Gervin English Ale yeast, which is Nottingham in a different packet and for half the price.

I totally understand that and agree wholeheartedly but... he basically said 'no questions asked yes or no'

he hopefully learnt a lot more from your replies in the long run though.

 

[Belter]

do yiu have any evidence that Gervin and Nottingham are the same

 

[ontor]

Thanks all, I did learn a lot

Basically, my brew is still brewing after 10 days

This has been at an average of 17 degrees

I have now purchased a couple of the electric 5 gallon FV warming plates and 2 FV's to suit and have started a second brew. This one is running at 24 degrees on one of the plates, the first one is still at 18 as this is the house temp. Im therefore going to put it on the second heater plate to hasten the completion of the process.

The original FV is a bit too big (larger diameter,shorter height) I will calculate the risks involved in transferring to the second new FV which fits the plate, to complete the first stage of fermentation on this now 10 day old brew. As long as i'm careful and very clean, I see no potential problems in this operation. Or then again, I might just sit the oversize FV on the plate.

Opinions will vary I expect from that's insane to go on and do it.


Cheers

Al

 

[graysalchemy]

One point no one really touched on is that different temps will give different flavour profiles. If you brew at lower temps you will lose out on the esters which give ale its characteristic fruity notes. Brew too high and you are into the fusel alcohol temps which PD noted which not only taste solventy but will also give hangovers.

 

[ontor]

One point no one really touched on is that different temps will give different flavour profiles. If you brew at lower temps you will lose out on the esters which give ale its characteristic fruity notes. Brew too high and you are into the fusel alcohol temps which PD noted which not only taste solventy but will also give hangovers.

Its funny you should say that,

I DID swap to the new FV and put it on the heater. Its running at 22 now so 5 degree hike up from 17 average and its off like a good un!

It smells much fruitier and cheekier and altogether more pleasing. (it was not unpleasant before) but it smells like a different beer now.

I hope to have it in the pressure barrel by Friday :